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What happens if you run out of stones?
http://www.lifein19x19.com/viewtopic.php?f=11&t=4860		 Page 1 of 2
Author:  skan [ Wed Oct 19, 2011 7:12 am ]
Post subject:  What happens if you run out of stones?
Hello

Imagine your opponent captured a lot of your stones and you have already placed the remaining on the board.
There is still room to play but you don't have more stones.
Author:  Li Kao [ Wed Oct 19, 2011 7:23 am ]
Post subject:  Re: What happens if you run out stones?
In theory the problem is easy: You have infinite stones.

In practice you usually exchange prisoners. While there might not be enough prisoners one one side, the game should be decided at that point. So that problem doesn't turn up in practice.
Author:  entropi [ Wed Oct 19, 2011 7:51 am ]
Post subject:  Re: What happens if you run out stones?
Li Kao wrote:
In theory the problem is easy: You have infinite stones.

In practice you usually exchange prisoners. While there might not be enough prisoners one one side, the game should be decided at that point. So that problem doesn't turn up in practice.


It did! I run out of stones in one of my games, even after exchanging prisoners. I had to borrow stones from my neighbour player. Not to mention that we were in byo-yomi at that late stage of the game.
Author:  gaius [ Wed Oct 19, 2011 9:05 am ]
Post subject:  Re: What happens if you run out of stones?
entropi, you already give the solution :)

If there are not enough stones, just pause the clock and pick up a couple of stones from your neighbour or from wherever.
Author:  xed_over [ Wed Oct 19, 2011 9:09 am ]
Post subject:  Re: What happens if you run out of stones?
180 stones each should be enough for anybody
Author:  p2501 [ Wed Oct 19, 2011 9:13 am ]
Post subject:  Re: What happens if you run out of stones?
Well if you play with progressive byo-yomi and get into it early in the game, there can be a point when there are not enough stones for the next cycle.
Author:  RobertJasiek [ Wed Oct 19, 2011 10:18 am ]
Post subject:  Re: What happens if you run out of stones?
Non-Ing Rules: The number of stones is arbitrarily great.

Ing-Rules: It is undefined (what happens if all 180 stones of a player are on the board).
Author:  xed_over [ Wed Oct 19, 2011 11:38 am ]
Post subject:  Re: What happens if you run out of stones?
RobertJasiek wrote:
Ing-Rules: It is undefined (what happens if all 180 stones of a player are on the board).

then maybe he should pass -- since it obviously means his opponent must have had many many captures and is now way behind; otherwise if both players had 180 stones on the board, there would only be one point on the boar left to play
Author:  Li Kao [ Wed Oct 19, 2011 12:20 pm ]
Post subject:  Re: What happens if you run out of stones?
xed_over wrote:
RobertJasiek wrote:
Ing-Rules: It is undefined (what happens if all 180 stones of a player are on the board).

then maybe he should pass -- since it obviously means his opponent must have had many many captures and is now way behind; otherwise if both players had 180 stones on the board, there would only be one point on the boar left to play

Not necessarily. If both sides had many dead stones, but only those of one side were taken off the board, the other side might have 180 stones on the board, while still being behind.
Author:  xed_over [ Wed Oct 19, 2011 1:57 pm ]
Post subject:  Re: What happens if you run out of stones?
Li Kao wrote:
xed_over wrote:
RobertJasiek wrote:
Ing-Rules: It is undefined (what happens if all 180 stones of a player are on the board).

then maybe he should pass -- since it obviously means his opponent must have had many many captures and is now way behind; otherwise if both players had 180 stones on the board, there would only be one point on the boar left to play

Not necessarily. If both sides had many dead stones, but only those of one side were taken off the board, the other side might have 180 stones on the board, while still being behind.

not possible

180 is half the board (Ing rules are area counting). No way to have more than half the board and be behind.
Author:  daniel_the_smith [ Wed Oct 19, 2011 1:59 pm ]
Post subject:  Re: What happens if you run out of stones?
xed_over wrote:
Li Kao wrote:
xed_over wrote:
then maybe he should pass -- since it obviously means his opponent must have had many many captures and is now way behind; otherwise if both players had 180 stones on the board, there would only be one point on the boar left to play

Not necessarily. If both sides had many dead stones, but only those of one side were taken off the board, the other side might have 180 stones on the board, while still being behind.

not possible

180 is half the board (Ing rules are area counting). No way to have more than half the board and be behind.


Meh, I've lost groups bigger than that. ;)
Author:  Li Kao [ Wed Oct 19, 2011 2:09 pm ]
Post subject:  Re: What happens if you run out of stones?
xed_over wrote:
Li Kao wrote:
xed_over wrote:
then maybe he should pass -- since it obviously means his opponent must have had many many captures and is now way behind; otherwise if both players had 180 stones on the board, there would only be one point on the boar left to play

Not necessarily. If both sides had many dead stones, but only those of one side were taken off the board, the other side might have 180 stones on the board, while still being behind.

not possible

180 is half the board (Ing rules are area counting). No way to have more than half the board and be behind.

Having 180 living stones wins you the game, yes. But if many of those stones are dead, but still on the board, you can be behind.
Author:  jts [ Wed Oct 19, 2011 2:33 pm ]
Post subject:  Re: What happens if you run out of stones?
Li Kao wrote:
Having 180 living stones wins you the game, yes. But if many of those stones are dead, but still on the board, you can be behind.

This is what we're not sure about. If one player has played 180 stones which are still on the board, the other player also has played 180 stones that were not in kos. So the only remaining empty points on the board are the spaces made by a capture of some of the second player's stones. But that implies that whichever of the second player's 180 plays are still on the board, they have no eyes.

Can you come up with a board where black has 180 stones on the board, white has 180 stones on the board minus whatever captures black has made, it's black to move, and black has not just won an overwhelming victory?
Author:  yoyoma [ Wed Oct 19, 2011 3:09 pm ]
Post subject:  Re: What happens if you run out of stones?
xed_over wrote:
180 is half the board (Ing rules are area counting). No way to have more than half the board and be behind.


Black needs 185 points to win because of komi.
Author:  Redbeard [ Wed Oct 19, 2011 3:23 pm ]
Post subject:  Re: What happens if you run out of stones?
If you have played 180 stones and your opponent has played 180 stones and no one has won the game you're doing it wrong. Start over and concentrate on making territory this time, not capturing stones. This ain't checkers. :mrgreen:
Author:  Li Kao [ Wed Oct 19, 2011 3:26 pm ]
Post subject:  Re: What happens if you run out of stones?
jts wrote:
Li Kao wrote:
Having 180 living stones wins you the game, yes. But if many of those stones are dead, but still on the board, you can be behind.

This is what we're not sure about. If one player has played 180 stones which are still on the board, the other player also has played 180 stones that were not in kos. So the only remaining empty points on the board are the spaces made by a capture of some of the second player's stones. But that implies that whichever of the second player's 180 plays are still on the board, they have no eyes.

Can you come up with a board where black has 180 stones on the board, white has 180 stones on the board minus whatever captures black has made, it's black to move, and black has not just won an overwhelming victory?

For unrealistic boards it's easy. Just think of black having a 180 stone blob without eyes but still a few liberties. And white having most of the rest of the board, with eyes. And then add white prisoners corresponding to the amount of free points.

if this can happen in a real game between decent players is another question.
Author:  Solomon [ Wed Oct 19, 2011 3:31 pm ]
Post subject:  Re: What happens if you run out of stones?
Now come on guys, what if he ends up with this board position?



edit: Or I suppose it won't matter if you just re-use prisoners? Oh well, it's still a cool thing to look at.
Author:  Li Kao [ Wed Oct 19, 2011 3:33 pm ]
Post subject:  Re: What happens if you run out of stones?
Araban: While cute, this situation can be solved with a prisoner exchange.
Author:  Solomon [ Wed Oct 19, 2011 3:35 pm ]
Post subject:  Re: What happens if you run out of stones?
Li Kao wrote:
Araban: While cute, this situation can be solved with a prisoner exchange.
Yeah, I just realized this as soon as I posted :P. Ah well.
Author:  jts [ Wed Oct 19, 2011 4:17 pm ]
Post subject:  Re: What happens if you run out of stones?
Li Kao wrote:
For unrealistic boards it's easy. Just think of black having a 180 stone blob without eyes but still a few liberties. And white having most of the rest of the board, with eyes. And then add white prisoners corresponding to the amount of free points.


Well, it's white's eyes that are the problem. If black has 180 stones on the board and white doesn't, then at least some of blacks stones must have liberties, because black has captured white stones. But white can only have a maximum of X+1 liberties for all of his groups combined, where X is the number of stones he has played inside the the areas where black has made captures.
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